Royalty stacking

Royalty stacking refers to the accumulation of royalties claimed by multiple holders of complementary patents, in particular standard-essential patents (SEPs), whose use is necessary to implement the same standard or commercialise the same product. Where each patent holder determines its royalty independently of the amounts claimed by the others, the aggregate royalty burden may become disproportionate to the overall value of the standardised technology or the end product, thereby increasing the cost of commercialisation or even making it commercially unviable.